High-voltage switches with a high peak current capability and precise, repeatable performance are needed for operating capacitive discharge units (CDUs) for many applications including the initiation of explosives, the triggering of airbags and camera flash units, etc. Current high-voltage vacuum switches require piece-part assembly which makes them relatively expensive for many applications. Additionally, piece-part assembly results in variations in assembly which can affect the operating characteristics of the devices. What is needed is a way of batch fabricating high-voltage vacuum switches to reduce the cost and improve the reliability of electrical vacuum switches.
The present invention addresses this need for batch fabricating high-voltage vacuum switches by providing an electrical vacuum switch apparatus that comprises an anode, a cathode and a trigger electrode which can all be microfabricated on the same substrate. A completed vacuum switch can then be formed according to the present invention by attaching a cover over the substrate under vacuum to provide a vacuum environment wherein the anode, cathode and trigger electrode are located.
An advantage of the electrical vacuum switch apparatus of the present invention is that a relatively large number (up to hundreds or more) of individual devices can be batch fabricated on a common substrate without piece part assembly.
Another advantage of the electrical vacuum switch apparatus of the present invention is that various types of carbon materials can be used in the trigger electrode to provide electron emission for initiating a vacuum arc therein including graphitic carbon, diamond-like materials, and carbon nanotubes.
Yet another advantage of the electrical vacuum switch apparatus of the present invention is that one or more channels can be formed extending below a surface of the substrate whereon the anode and cathode are located to prevent surface breakdown on the substrate during operation of the device.
Still another advantage is that a metal cover can be used to trigger the vacuum arc in the electrical vacuum switch apparatus of the present invention, and to channel at least a portion of the arc.
These and other advantages of the present invention will become evident to those skilled in the art.